[Ffmpeg-devel] [PATCH] Replace av_malloc+memset with av_mallocz

[Panagiotis Issaris]

Hi,

Op woensdag 6 september 2006 15:53, schreef Michael Niedermayer:
>[...] 
> > AFAIK, it's because memory allocation fails, if a disaster occurs
> > (badly OOM for instance, ...) and means that my may be better off
> > killing the prgm as the OS will probably kill some prgm to free some
> > memory. So by not checking if allocation succeeds, you just guarantee
> > that in case of OOM, you will be killed by a segfault rather than
> > being killed by the kernel OOM killer.
> 
> this isnt the whole story ...
> theres the issue with DOS attacks too (= files designed to cause OOM)
> so IMHO checking the sizes before alloc() if the size is specified in 
> some input file is a good idea ...

But how would you do that? Check for the allocation of "really big" 
blocks of memory? It doesn't seem that easy to me to define such a
maximum.

And moreover, would that be enough, wouldn't it be possible to construct 
a file that makes FFmpeg do many smaller allocations, causing OOM?

With friendly regards,
Takis